Cubix is freeware drumsynth/sampleplayer with an onboard arpeggiated bassline synth for Windows PC.

Cubix has 4 drum sections (Kick, Snare, Hihat and Perc, but they can be anything really) which can be randomized, mixed and matched. It's real easy to get a cool beat going and you can manipulate a lot on the fly. Add a bass synth with arpeggiator and plenty modulation options and you're all set to get a serious groove going (and have some serious fun while you're at it)!

basic 64 is inspired by the 8 bit sounds of the classic Commodore 64. It's not a straight emulation but is based around the SID chip with some extras for that 8-bit retro game sound, lofi gritty noises or just plain oddness.